azygos

[ăzĭ-gŏs′, ā-zīgŏs′]
adj.
  1. Not one of a pair, as a vein or muscle; occurring singly.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Examples from the Web for azygos

Historical Examples of azygos